The present invention relates to an improved method and apparatus for dispensing a rinse water additive in an automatic washing machine.
The present invention further relates to such a method and apparatus which is suited to both liquid and solid rinse water additives which are generally highly concentrated and added in relatively small volumes, thereby making accurate measurement and avoidance of leakage during the wash cycle critical to obtaining the desired benefits to be provided by the additive during the rinse cycle.
Dosing dispensers for the addition of laundering and softening materials during the washing and rinsing cycles in an automatic washing machine are well known in the art.
Dispensers for adding materials during the rinse cycle in an automatic washer are generally more complex than those employed for adding materials during the wash cycle due to the fact that the rinse additive dispenser is normally inserted when the wash cycle begins and must survive the entire wash cycle without leakage or dispensing the material contained inside, yet reliably open during the spin cycle to deliver the rinse water additive at the point in time at which it will be more effective.
Rinse water additive dispensers commonly employ a valve that is automatically opened by the centrifugal forces acting upon a counterweight during the spin cycle at the conclusion of the wash operation. After the spin cycle, dispensers of the aforementioned type fall from the wall of the washing machine drum and rinse water floods the dispenser, mixing with and dispensing the additive into the rinse water. One prior art example of such a rinse additive dispenser is disclosed in U.S. Pat. No. 3,888,391 issued to Merz on Jun. 10, 1975 and hereby incorporated herein by reference. Another example of such a prior art rinse water additive dispenser is disclosed in U.S. Defensive Publication No. T993,001 to McCarthy, which was published on Apr. 1, 1980, and which is hereby incorporated herein by reference. Similar examples are found in U.S. Pat. No. 5,267,671, issued to Baginski et al. on Dec. 7, 1993 and U.S. Pat. No. 5,768,918 issued to McKibben on Jun. 23, 1998, both of which are incorporated herein by reference.
While dispensers of the aforementioned type have functioned adequately for their intended purpose with prior art rinse water additives, trends in the development of more effective rinse water additives have been in the direction of more specialized and/or highly concentrated additive products that can deliver a variety of performance benefits. Such additive products are not generally limited to free flowing liquids but can also include granules, agglomerates, more viscous pastes and gels, as well as solids and encapsulates. A disadvantage of the dispensing devices known in the art is that fact that the additives are delivered into the dispenser through the same opening that is sealed by the counterweight, an opening that is generally limited in size. Additional problems associated with these devices include the fact that the valve means is commonly not removable from this opening nor the counterweight from the internal chamber. In such a design, the presence of the valve means presents an obstacle that interferes with the introduction of flowable rinse additives into the dispenser leading to spillage and waste, as well as preventing the use of solid and encapsulated additives that can not pass through the partially obstructed opening.
An additional problem associated with the prior art dispensing devices is that it is commonly difficult to properly seat the valve means prior to the placement of the dispenser in the washing machine. When not properly seated, these valves tend to either dislodge prematurely during the wash cycle where rinse water additives give ineffective and unsatisfactory results or fail to open at all.
Accordingly, it is an object of the present invention to provide a dispensing apparatus having an improved valve seal design that simplifies the proper seating of the valve means and closure of the dispensing device. Protection against premature opening is extremely important for rinse additive dispensers, since premature opening of the dispenser during the wash cycle will most likely result in complete loss of the additive during the wash cycle.
It is another object of the present invention to provide a dispensing device having an improved design that will provide an unobstructed opening through which the dispenser may be filled with rinse water additives of various forms and sizes.
The present invention provides a rinse additive dispenser having an upper housing having a opening and a lower housing releasably connected to the upper housing, the housing walls defining an internal chamber for containing a rinse water laundry additive. The dispensers of the present invention further comprise a valve assembly having a valve for sealing the opening in the upper housing. The valve is movable between closed and open positions and is biased towards an open position. In addition, the dispensers of the present invention include a weight assembly having a counterweight that is actuated by centrifugal force and which prior to actuation prevents the valve from biasing to an open position.
In a further aspect of the present invention, the dispenser valve assembly has a valve retainer contained within the upper housing for retaining said valve, and biasing means for biasing the valve to an open position. Preferably, the means for biasing the valve to an open position is a coil spring. In addition, the valve is provided with a stem that extends through the valve retainer.
In yet a further aspect of the present invention, the dispenser weight assembly has a weight retainer contained within the lower housing for retaining the counterweight, and centering means to aid in centering the counterweight. In addition, the counterweight has a post that extends through the weight retainer and the centering means. Preferably, the centering means is a swivel joint. Alternatively, or in addition to, the centering means can include a resilient guide member affixed to the weight retainer around the post to bias the counterweight post to a centerline position.
In yet a further aspect of the present invention, the upper and lower housings of the dispensing device are releasably connected by threads, hinge, tongue and groove structures, magnets, or push-pull snap closures on the upper and lower housings respectively.